1 files changed, 58 insertions, 0 deletions
diff --git a/src/test/ui/associated-types/issue-65774-1.rs b/src/test/ui/associated-types/issue-65774-1.rs
new file mode 100644
index 000000000..934514055
--- /dev/null
+++ b/src/test/ui/associated-types/issue-65774-1.rs
@@ -0,0 +1,58 @@
+#![feature(associated_type_defaults)]
+
+trait MyDisplay { fn method(&self) { } }
+
+impl<'a, T: MyDisplay> MyDisplay for &'a mut T { }
+
+struct T;
+
+trait MPU {
+    type MpuConfig: MyDisplay = T;
+    //~^ ERROR the trait bound `T: MyDisplay` is not satisfied
+}
+
+struct S;
+
+impl MPU for S { }
+
+trait MyWrite {
+    fn my_write(&self, _: &dyn MyDisplay) { }
+}
+
+trait ProcessType {
+    fn process_detail_fmt(&self, _: &mut dyn MyWrite);
+}
+
+struct Process;
+
+impl ProcessType for Process {
+    fn process_detail_fmt(&self, writer: &mut dyn MyWrite)
+    {
+
+        let mut val: Option<<S as MPU>::MpuConfig> = None;
+        let valref: &mut <S as MPU>::MpuConfig = val.as_mut().unwrap();
+
+        // // This causes a different ICE (but its similar if you squint right):
+        // //
+        // // `Unimplemented` selecting `Binder(<T as MyDisplay>)` during codegen
+        //
+        // writer.my_write(valref)
+
+        // This one causes the ICE:
+        // FulfillmentError(Obligation(predicate=Binder(TraitPredicate(<T as MyDisplay>)),
+        // depth=1),Unimplemented)
+        let closure = |config: &mut <S as MPU>::MpuConfig| writer.my_write(&config);
+        //~^ ERROR the trait bound `T: MyDisplay` is not satisfied
+        closure(valref);
+    }
+}
+
+fn create() -> &'static dyn ProcessType {
+    let input: Option<&mut Process> = None;
+    let process: &mut Process = input.unwrap();
+    process
+}
+
+pub fn main() {
+    create();
+}